Exploration of uncooled quantum infrared detectors based on quantum dots/graphene heterostructures

摘要

Heterojunction nanohybrids based on low-dimension semiconductors, including colloidal quantum dots (QDs) and 2D atomic materials (graphene, transition metal chalcogenides, etc) provide a fascinating platform to design of new photonic and optoelectronic devices that take advantages of the enhanced light-solid interaction attributed to their strong quantum confinement and superior charge mobility for uncooled photodetectors with a high gain up to 10~(10). In these heterojunction nanohybrids, the van der Waals (vdW) interface plays a critical role in controlling the optoelectronic process including exciton dissociation by the interface built-in field that drives the follow-up charge injection and transport to graphene. In this paper, we present our recent progress in development of such heterostructures nanohybrids for uncooled infrared detectors including PbS and FeS_2 QDs/graphene and 2D vdW heterostructures MoTe_2/Graphene/SnS_2 and GaTe/InSe. We have found that nonstoichiometric Fe_(1-x)S_2 QDs (x = 0.01-0.107) with strong localized surface plasmonic resonance (LSPR) can have much enhanced absorption in broadband from ultraviolet to short-wave infrared (SWIR, 1-3 μm). Consequently, the LSPR Fe_(1-x)S_2 QDs/graphene heterostructure photodetectors exhibit extraordinary photoresponsivity in exceeding 4.32 × 10~6 A/W and figure-of-merit detectivity D* > 7.50 × 10~(12) Jones in the broadband of UV-Vis-SWIR at room temperature. The 2D vdW heterostructures allows novel designs of interface band alignments with uncooled NIR-SWIR D* up to 10~(12) Jones. These results illustrate that the heterostructure nanolybrids provide a promising pathway for low-cost, printable and flexible infrared detectors and imaging systems.